Monitoring patients presents challenges to healthcare professionals that are charged with patient care. These challenges are accentuated when the patients being monitored are ambulatory because the devices used for monitoring patient parameters are also required to be movable so that the patient is not confined to a particular bed in a particular care unit. There are a plurality of portable patient monitoring devices able to monitor different patient parameters. The monitored patient parameters may be transmitted over a wireless communications network for receipt by a central monitoring station. In order for these monitors to remain portable and enable patients to be ambulatory, these monitoring devices often include rechargeable batteries. However, a drawback associated with portable patient monitors that wirelessly transmit data is the need to maintain the monitors in a lower power state to maximize battery life while ensuring that there are no gaps in the data being transmitted and/or received by the monitors.
Furthermore, in order for patients to remain ambulatory, they should be able to wireless transmit data from and receive data at their respective monitoring devices. In a healthcare environment that is outfitted with a wireless network (e.g. 802.11a/b/d/g/i/n, etc), in order to consistently monitor the patients when they are moving between different care units, there are a plurality of access points positioned at various areas throughout the healthcare environment. The plurality of access points are coupled to at least one communications network that includes at least one monitoring station for collecting patient data. The collected patient data may, for example, be displayed on a display device or stored in a patient information database for the purpose of creating a patient healthcare record. In order for this patient data to be reliably collected, the portable patient monitors can selectively communicate with a respective one of the access points to transmit and receive data therebetween. While the patient is moving around the healthcare enterprise, the communication may be selectively handed off between successive access points depending on the proximity of the portable patient monitor to the respective access point. Proximity is determined based on a received signal strength indicator (RSSI) which is a measure of power. Thus, the portable patient monitors look for the highest RSSI value (or in some cases, the least negative RSSI value) which determines and identifies the “closest” access point. While RSSI value successfully determines the access point to which the portable patient monitor will connect in order to prevent a gap in data transmission, it is unable to avoid the transmission gap that often occurs when the portable patient monitor has already identified that a particular access point is the “closest” access point. Thus, a need exists to improve data transmission between monitoring devices and access points, when proximity to an access point is not the cause of the transmission gap. A system according to invention principles addresses deficiencies of known systems to reduce transmission gaps between portable monitoring devices that are connected to a central monitoring station via at least one wireless access point.